A sunscreen label carries two quite different kinds of writing: information whose meaning is defined by regulation, and description chosen by the manufacturer. Knowing which is which is most of what it takes to read one, and the regulated parts are published by the body that regulates them.
Why is a sunscreen label so hard to read?
Because a label is doing two jobs at once, and it does not tell you which is which.
Part of the writing on a sunscreen label carries a defined meaning. Certain information must appear, in certain forms, because a regulator has said so, and where a term is defined the manufacturer cannot simply decide what it means. The rest is description: the words chosen to make the product appealing, which are constrained by rules about misleading claims but are not defined terms.
Both appear in similar typefaces on the same label. Learning to separate them is the single skill this page is about, and it transfers to every product on the shelf.
What is regulated, and by whom?
In Great Britain, cosmetic products fall under the Office for Product Safety and Standards, which publishes guidance on what must appear on containers and packaging. That guidance covers matters such as who is responsible for the product, quantity, durability, precautions for use and the ingredient list.
Sunscreens sit within that framework and carry additional considerations of their own, because the protection they claim is testable and the test methods are agreed rather than invented per brand. The sun protection factor is obtained by a standardised method, and protection against the longer wavelengths is assessed by its own agreed approach.
What this page deliberately does not do is reproduce those requirements. They are published, they are revised, they are precise, and a paraphrase of a regulatory requirement is worth considerably less than the requirement. The guidance is linked below.
Which parts of a label carry information?
The sun protection factor is the number most people look for on a label. It refers to protection against the part of the spectrum principally responsible for burning, measured under laboratory conditions with a controlled quantity applied to the skin. Two things follow from that. The number describes a test, and the relationship between successive numbers is not proportional, so the intuition that twice the number means twice the protection does not hold.
Protection against the longer ultraviolet wavelengths is indicated separately, because it is a different question assessed by a different method. A product can perform well on one and less well on the other, which is precisely why both are indicated rather than combined into a single score.
The ingredient list is the part nobody reads and the part a clinician finds most useful. If you have reacted to something before, this is where the answer is, and it is why bringing the actual container to an appointment beats bringing the brand name.
Durability information matters more with sunscreen than with most cosmetics, given that a bottle frequently spends a year in a cupboard between summers.
What on a label is description rather than information?
Words on the front of the label chosen for effect: gentle, advanced, invisible, dermatologically something. Some are constrained by rules against misleading claims and some carry no defined meaning at all, but none of them is a measurement.
Texture and format claims fall into a middle category. They describe something real about how the product feels and behaves, which genuinely matters, because a sunscreen unpleasant enough to be applied sparingly protects worse than a duller one applied properly. That is a practical consideration rather than a regulated one.
Claims on the label about resistance to water or sweat are worth particular attention. They are meaningful claims subject to rules, but what they permit and require is a regulatory matter, and the published guidance is the place to establish it rather than a general article.
What this page does not do
It gives no factor numbers, no thresholds, no recommendation about which product to choose and no application instructions. Recommended factors and application advice are published by health authorities in each country, they change, and they are linked below to be read at source. Nothing here is a product recommendation.
Common questions
What does the SPF number refer to?
It refers to protection against the part of the ultraviolet spectrum principally responsible for burning, measured by a standardised test. It is a laboratory measure obtained under controlled application, which is why the relationship between the number and real-world protection is discussed so often.
Does a higher SPF mean proportionally more protection?
No, and the assumption that it does is one reason labels are confusing. The relationship is not linear, and the practical difference between adjacent high numbers is smaller than the numbers suggest. What the published guidance recommends is stated by the health bodies that publish it.
What does UVA protection on a label mean?
It refers to protection against a different part of the ultraviolet spectrum from the one the SPF number describes, assessed by its own agreed method. Whether and how it must be indicated is a matter of regulation rather than of manufacturer preference.
Who regulates what a sunscreen label must say in Great Britain?
Cosmetic products in Great Britain, sunscreens included, fall under the Office for Product Safety and Standards, which publishes guidance on what containers and packaging must display. That guidance is linked in the sources below and is the place to read the requirements.
Is water resistant a regulated term?
Claims made on cosmetic packaging are subject to rules, but exactly which claims are permitted and how they must be substantiated is a regulatory question rather than one a general page should answer from memory. The published guidance is the reliable place to check it.
Sources
- Making cosmetic products available to consumers in Great Britain — Office for Product Safety and Standards, Department for Business and Trade (Great Britain) · accessed
- Sunscreen and sun safety — NHS (United Kingdom) · accessed
Last updated . How this page was written.